This invention relates generally to rotary impulse sprinklers of the type generally described in U.S. Pat. Nos. 1,997,901 and 2,380,101. More specifically, this invention relates to an improved deflector spoon for use with a rotary impulse sprinkler, and for providing substantially consistent sprinkler operation regardless of the specific sprinkler nozzle geometry.
Rotary impulse sprinklers in general are well known in the art. Such sprinklers typically comprise a journalled sprinkler body with a sprinkler nozzle for directing a collimated water stream upwardly and outwardly. The sprinkler body carries an oscillating lever including a deflector spoon springably biased into engagement with the water stream. The spoon is geometrically configured to be driven by the water stream against the force of the spring to cause a portion of the lever to impact the sprinkler body and thereby rotate the sprinkler body. After impact, the spring once again urges the deflector spoon back into engagement with the water stream, whereby the oscillating lever rotates the sprinkler body in a continuous sequence of small angular steps. The sprinkler body may be designed to rotate through a complete circle, or may include a conventional reversing mechanism for causing the sprinkler body to oscillate repeatedly through a partial circle.
While rotary impulse sprinklers are widely used, th operating characteristics of these sprinklers are susceptible to various parameters such as water pressure,nozzle size and trajectory, and deflector spoon geometry. Of these parameters, nozzle configuration is particularly important since these impulse-type sprinklers are frequently designed for receiving interchangeable nozzles suited for a specific sprinkler operating environment. That is, a given sprinkler body and deflector spoon design may be adapted readily for any of a variety of desired operating characteristics by selection of the specific nozzle design. For example, a nozzle with a raised or lowered trajectory may be provided where the sprinkler is used in windy conditions, or is required to spray over or under shrubs or trees or the like. However, for optimum operation, it is desirable to design the deflector spoon so that it moves into and out of the water stream at substantially a constant rate regardless of the geometry of the water stream emanating from the sprinkler nozzle. Accordingly, it is desirable to provide a deflector spoon geometry which provides substantially similar operating characteristics regardless of the nozzle configuration, and thereby accommodates a variety of nozzles.
In the prior art, various deflector spoon geometries have been proposed in an attempt to provide relatively consistent deflector spoon operation with a variety of nozzle geometries. However, these proposed spoon designs have relied upon a minimization of spoon surface for reacting with the water stream by providing a deflector spoon geometry with one or more cutout portions. See, for example, U.S. Pat. No. 3,726,479 wherein upper and lower portions of the deflector spoon are omitted, and U.S. Pat. No. 3,930,617 wherein the central portion of the deflector spoon is omitted. However, these deflector spoon geometries are unsatisfactory for use with nozzle geometries of varying trajectory, since the water stream from some nozzles will fail to react with the deflector spoon sufficiently for proper operation.
The present invention overcomes the problems and disadvantages of the prior art by providing a specifically configured deflector spoon geometry for an impulse sprinkler, wherein the deflector spoon is designed for substantially similar operating characteristics regardless of the sprinkler nozzle trajectory.